vmalloc.c 68.1 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7
/*
 *  linux/mm/vmalloc.c
 *
 *  Copyright (C) 1993  Linus Torvalds
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
 *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
Christoph Lameter's avatar
Christoph Lameter committed
8
 *  Numa awareness, Christoph Lameter, SGI, June 2005
Linus Torvalds's avatar
Linus Torvalds committed
9 10
 */

Nick Piggin's avatar
Nick Piggin committed
11
#include <linux/vmalloc.h>
Linus Torvalds's avatar
Linus Torvalds committed
12 13 14
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
15
#include <linux/sched.h>
Linus Torvalds's avatar
Linus Torvalds committed
16 17 18
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
19
#include <linux/proc_fs.h>
20
#include <linux/seq_file.h>
21
#include <linux/debugobjects.h>
22
#include <linux/kallsyms.h>
Nick Piggin's avatar
Nick Piggin committed
23 24 25 26
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
27
#include <linux/pfn.h>
28
#include <linux/kmemleak.h>
Arun Sharma's avatar
Arun Sharma committed
29
#include <linux/atomic.h>
30
#include <linux/compiler.h>
31
#include <linux/llist.h>
32
#include <linux/bitops.h>
33

Linus Torvalds's avatar
Linus Torvalds committed
34 35
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
36
#include <asm/shmparam.h>
Linus Torvalds's avatar
Linus Torvalds committed
37

38 39
#include "internal.h"

40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58
struct vfree_deferred {
	struct llist_head list;
	struct work_struct wq;
};
static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);

static void __vunmap(const void *, int);

static void free_work(struct work_struct *w)
{
	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
	struct llist_node *llnode = llist_del_all(&p->list);
	while (llnode) {
		void *p = llnode;
		llnode = llist_next(llnode);
		__vunmap(p, 1);
	}
}

Nick Piggin's avatar
Nick Piggin committed
59
/*** Page table manipulation functions ***/
60

Linus Torvalds's avatar
Linus Torvalds committed
61 62 63 64 65 66 67 68 69 70 71
static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
		pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
		WARN_ON(!pte_none(ptent) && !pte_present(ptent));
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
72
static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
73 74 75 76 77 78 79
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
80 81
		if (pmd_clear_huge(pmd))
			continue;
Linus Torvalds's avatar
Linus Torvalds committed
82 83 84 85 86 87
		if (pmd_none_or_clear_bad(pmd))
			continue;
		vunmap_pte_range(pmd, addr, next);
	} while (pmd++, addr = next, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
88
static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
89 90 91 92 93 94 95
{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
96 97
		if (pud_clear_huge(pud))
			continue;
Linus Torvalds's avatar
Linus Torvalds committed
98 99 100 101 102 103
		if (pud_none_or_clear_bad(pud))
			continue;
		vunmap_pmd_range(pud, addr, next);
	} while (pud++, addr = next, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
104
static void vunmap_page_range(unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
{
	pgd_t *pgd;
	unsigned long next;

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
		vunmap_pud_range(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
Nick Piggin's avatar
Nick Piggin committed
120
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
121 122 123
{
	pte_t *pte;

Nick Piggin's avatar
Nick Piggin committed
124 125 126 127 128
	/*
	 * nr is a running index into the array which helps higher level
	 * callers keep track of where we're up to.
	 */

129
	pte = pte_alloc_kernel(pmd, addr);
Linus Torvalds's avatar
Linus Torvalds committed
130 131 132
	if (!pte)
		return -ENOMEM;
	do {
Nick Piggin's avatar
Nick Piggin committed
133 134 135 136 137
		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
Linus Torvalds's avatar
Linus Torvalds committed
138 139
			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
Nick Piggin's avatar
Nick Piggin committed
140
		(*nr)++;
Linus Torvalds's avatar
Linus Torvalds committed
141 142 143 144
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
145 146
static int vmap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
147 148 149 150 151 152 153 154 155
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
156
		if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
157 158 159 160 161
			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
162 163
static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
164 165 166 167 168 169 170 171 172
{
	pud_t *pud;
	unsigned long next;

	pud = pud_alloc(&init_mm, pgd, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
173
		if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
174 175 176 177 178
			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
179 180 181 182 183 184
/*
 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
 * will have pfns corresponding to the "pages" array.
 *
 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
 */
185 186
static int vmap_page_range_noflush(unsigned long start, unsigned long end,
				   pgprot_t prot, struct page **pages)
Linus Torvalds's avatar
Linus Torvalds committed
187 188 189
{
	pgd_t *pgd;
	unsigned long next;
190
	unsigned long addr = start;
Nick Piggin's avatar
Nick Piggin committed
191 192
	int err = 0;
	int nr = 0;
Linus Torvalds's avatar
Linus Torvalds committed
193 194 195 196 197

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
198
		err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
Linus Torvalds's avatar
Linus Torvalds committed
199
		if (err)
200
			return err;
Linus Torvalds's avatar
Linus Torvalds committed
201
	} while (pgd++, addr = next, addr != end);
Nick Piggin's avatar
Nick Piggin committed
202 203

	return nr;
Linus Torvalds's avatar
Linus Torvalds committed
204 205
}

206 207 208 209 210 211 212 213 214 215
static int vmap_page_range(unsigned long start, unsigned long end,
			   pgprot_t prot, struct page **pages)
{
	int ret;

	ret = vmap_page_range_noflush(start, end, prot, pages);
	flush_cache_vmap(start, end);
	return ret;
}

216
int is_vmalloc_or_module_addr(const void *x)
217 218
{
	/*
219
	 * ARM, x86-64 and sparc64 put modules in a special place,
220 221 222 223 224 225 226 227 228 229 230
	 * and fall back on vmalloc() if that fails. Others
	 * just put it in the vmalloc space.
	 */
#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
	unsigned long addr = (unsigned long)x;
	if (addr >= MODULES_VADDR && addr < MODULES_END)
		return 1;
#endif
	return is_vmalloc_addr(x);
}

231
/*
232
 * Walk a vmap address to the struct page it maps.
233
 */
234
struct page *vmalloc_to_page(const void *vmalloc_addr)
235 236
{
	unsigned long addr = (unsigned long) vmalloc_addr;
237
	struct page *page = NULL;
238 239
	pgd_t *pgd = pgd_offset_k(addr);

240 241 242 243
	/*
	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
	 * architectures that do not vmalloc module space
	 */
244
	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
Jiri Slaby's avatar
Jiri Slaby committed
245

246
	if (!pgd_none(*pgd)) {
Nick Piggin's avatar
Nick Piggin committed
247
		pud_t *pud = pud_offset(pgd, addr);
248
		if (!pud_none(*pud)) {
Nick Piggin's avatar
Nick Piggin committed
249
			pmd_t *pmd = pmd_offset(pud, addr);
250
			if (!pmd_none(*pmd)) {
Nick Piggin's avatar
Nick Piggin committed
251 252
				pte_t *ptep, pte;

253 254 255
				ptep = pte_offset_map(pmd, addr);
				pte = *ptep;
				if (pte_present(pte))
256
					page = pte_page(pte);
257 258 259 260
				pte_unmap(ptep);
			}
		}
	}
261
	return page;
262
}
263
EXPORT_SYMBOL(vmalloc_to_page);
264 265

/*
266
 * Map a vmalloc()-space virtual address to the physical page frame number.
267
 */
268
unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
269
{
270
	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
271
}
272
EXPORT_SYMBOL(vmalloc_to_pfn);
273

Nick Piggin's avatar
Nick Piggin committed
274 275 276 277 278 279 280 281

/*** Global kva allocator ***/

#define VM_LAZY_FREE	0x01
#define VM_LAZY_FREEING	0x02
#define VM_VM_AREA	0x04

static DEFINE_SPINLOCK(vmap_area_lock);
282 283
/* Export for kexec only */
LIST_HEAD(vmap_area_list);
Nick Piggin's avatar
Nick Piggin committed
284 285 286 287 288 289 290 291
static struct rb_root vmap_area_root = RB_ROOT;

/* The vmap cache globals are protected by vmap_area_lock */
static struct rb_node *free_vmap_cache;
static unsigned long cached_hole_size;
static unsigned long cached_vstart;
static unsigned long cached_align;

292
static unsigned long vmap_area_pcpu_hole;
Nick Piggin's avatar
Nick Piggin committed
293 294

static struct vmap_area *__find_vmap_area(unsigned long addr)
Linus Torvalds's avatar
Linus Torvalds committed
295
{
Nick Piggin's avatar
Nick Piggin committed
296 297 298 299 300 301 302 303
	struct rb_node *n = vmap_area_root.rb_node;

	while (n) {
		struct vmap_area *va;

		va = rb_entry(n, struct vmap_area, rb_node);
		if (addr < va->va_start)
			n = n->rb_left;
304
		else if (addr >= va->va_end)
Nick Piggin's avatar
Nick Piggin committed
305 306 307 308 309 310 311 312 313 314 315 316 317 318 319
			n = n->rb_right;
		else
			return va;
	}

	return NULL;
}

static void __insert_vmap_area(struct vmap_area *va)
{
	struct rb_node **p = &vmap_area_root.rb_node;
	struct rb_node *parent = NULL;
	struct rb_node *tmp;

	while (*p) {
320
		struct vmap_area *tmp_va;
Nick Piggin's avatar
Nick Piggin committed
321 322

		parent = *p;
323 324
		tmp_va = rb_entry(parent, struct vmap_area, rb_node);
		if (va->va_start < tmp_va->va_end)
Nick Piggin's avatar
Nick Piggin committed
325
			p = &(*p)->rb_left;
326
		else if (va->va_end > tmp_va->va_start)
Nick Piggin's avatar
Nick Piggin committed
327 328 329 330 331 332 333 334
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&va->rb_node, parent, p);
	rb_insert_color(&va->rb_node, &vmap_area_root);

335
	/* address-sort this list */
Nick Piggin's avatar
Nick Piggin committed
336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357
	tmp = rb_prev(&va->rb_node);
	if (tmp) {
		struct vmap_area *prev;
		prev = rb_entry(tmp, struct vmap_area, rb_node);
		list_add_rcu(&va->list, &prev->list);
	} else
		list_add_rcu(&va->list, &vmap_area_list);
}

static void purge_vmap_area_lazy(void);

/*
 * Allocate a region of KVA of the specified size and alignment, within the
 * vstart and vend.
 */
static struct vmap_area *alloc_vmap_area(unsigned long size,
				unsigned long align,
				unsigned long vstart, unsigned long vend,
				int node, gfp_t gfp_mask)
{
	struct vmap_area *va;
	struct rb_node *n;
Linus Torvalds's avatar
Linus Torvalds committed
358
	unsigned long addr;
Nick Piggin's avatar
Nick Piggin committed
359
	int purged = 0;
Nick Piggin's avatar
Nick Piggin committed
360
	struct vmap_area *first;
Nick Piggin's avatar
Nick Piggin committed
361

Nick Piggin's avatar
Nick Piggin committed
362
	BUG_ON(!size);
363
	BUG_ON(offset_in_page(size));
Nick Piggin's avatar
Nick Piggin committed
364
	BUG_ON(!is_power_of_2(align));
Nick Piggin's avatar
Nick Piggin committed
365 366 367 368 369 370

	va = kmalloc_node(sizeof(struct vmap_area),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!va))
		return ERR_PTR(-ENOMEM);

371 372 373 374 375 376
	/*
	 * Only scan the relevant parts containing pointers to other objects
	 * to avoid false negatives.
	 */
	kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);

Nick Piggin's avatar
Nick Piggin committed
377 378
retry:
	spin_lock(&vmap_area_lock);
Nick Piggin's avatar
Nick Piggin committed
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402
	/*
	 * Invalidate cache if we have more permissive parameters.
	 * cached_hole_size notes the largest hole noticed _below_
	 * the vmap_area cached in free_vmap_cache: if size fits
	 * into that hole, we want to scan from vstart to reuse
	 * the hole instead of allocating above free_vmap_cache.
	 * Note that __free_vmap_area may update free_vmap_cache
	 * without updating cached_hole_size or cached_align.
	 */
	if (!free_vmap_cache ||
			size < cached_hole_size ||
			vstart < cached_vstart ||
			align < cached_align) {
nocache:
		cached_hole_size = 0;
		free_vmap_cache = NULL;
	}
	/* record if we encounter less permissive parameters */
	cached_vstart = vstart;
	cached_align = align;

	/* find starting point for our search */
	if (free_vmap_cache) {
		first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
403
		addr = ALIGN(first->va_end, align);
Nick Piggin's avatar
Nick Piggin committed
404 405
		if (addr < vstart)
			goto nocache;
406
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
407 408 409 410
			goto overflow;

	} else {
		addr = ALIGN(vstart, align);
411
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
412 413 414 415 416 417
			goto overflow;

		n = vmap_area_root.rb_node;
		first = NULL;

		while (n) {
Nick Piggin's avatar
Nick Piggin committed
418 419 420 421
			struct vmap_area *tmp;
			tmp = rb_entry(n, struct vmap_area, rb_node);
			if (tmp->va_end >= addr) {
				first = tmp;
Nick Piggin's avatar
Nick Piggin committed
422 423 424 425
				if (tmp->va_start <= addr)
					break;
				n = n->rb_left;
			} else
Nick Piggin's avatar
Nick Piggin committed
426
				n = n->rb_right;
Nick Piggin's avatar
Nick Piggin committed
427
		}
Nick Piggin's avatar
Nick Piggin committed
428 429 430 431

		if (!first)
			goto found;
	}
Nick Piggin's avatar
Nick Piggin committed
432 433

	/* from the starting point, walk areas until a suitable hole is found */
434
	while (addr + size > first->va_start && addr + size <= vend) {
Nick Piggin's avatar
Nick Piggin committed
435 436
		if (addr + cached_hole_size < first->va_start)
			cached_hole_size = first->va_start - addr;
437
		addr = ALIGN(first->va_end, align);
438
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
439 440
			goto overflow;

441
		if (list_is_last(&first->list, &vmap_area_list))
Nick Piggin's avatar
Nick Piggin committed
442
			goto found;
443 444 445

		first = list_entry(first->list.next,
				struct vmap_area, list);
Nick Piggin's avatar
Nick Piggin committed
446 447
	}

Nick Piggin's avatar
Nick Piggin committed
448 449 450
found:
	if (addr + size > vend)
		goto overflow;
Nick Piggin's avatar
Nick Piggin committed
451 452 453 454 455

	va->va_start = addr;
	va->va_end = addr + size;
	va->flags = 0;
	__insert_vmap_area(va);
Nick Piggin's avatar
Nick Piggin committed
456
	free_vmap_cache = &va->rb_node;
Nick Piggin's avatar
Nick Piggin committed
457 458
	spin_unlock(&vmap_area_lock);

Nick Piggin's avatar
Nick Piggin committed
459 460 461 462
	BUG_ON(va->va_start & (align-1));
	BUG_ON(va->va_start < vstart);
	BUG_ON(va->va_end > vend);

Nick Piggin's avatar
Nick Piggin committed
463
	return va;
Nick Piggin's avatar
Nick Piggin committed
464 465 466 467 468 469 470 471 472

overflow:
	spin_unlock(&vmap_area_lock);
	if (!purged) {
		purge_vmap_area_lazy();
		purged = 1;
		goto retry;
	}
	if (printk_ratelimit())
473
		pr_warn("vmap allocation for size %lu failed: "
Nick Piggin's avatar
Nick Piggin committed
474 475 476
			"use vmalloc=<size> to increase size.\n", size);
	kfree(va);
	return ERR_PTR(-EBUSY);
Nick Piggin's avatar
Nick Piggin committed
477 478 479 480 481
}

static void __free_vmap_area(struct vmap_area *va)
{
	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
Nick Piggin's avatar
Nick Piggin committed
482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497

	if (free_vmap_cache) {
		if (va->va_end < cached_vstart) {
			free_vmap_cache = NULL;
		} else {
			struct vmap_area *cache;
			cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
			if (va->va_start <= cache->va_start) {
				free_vmap_cache = rb_prev(&va->rb_node);
				/*
				 * We don't try to update cached_hole_size or
				 * cached_align, but it won't go very wrong.
				 */
			}
		}
	}
Nick Piggin's avatar
Nick Piggin committed
498 499 500 501
	rb_erase(&va->rb_node, &vmap_area_root);
	RB_CLEAR_NODE(&va->rb_node);
	list_del_rcu(&va->list);

502 503 504 505 506 507 508 509 510
	/*
	 * Track the highest possible candidate for pcpu area
	 * allocation.  Areas outside of vmalloc area can be returned
	 * here too, consider only end addresses which fall inside
	 * vmalloc area proper.
	 */
	if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
		vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);

511
	kfree_rcu(va, rcu_head);
Nick Piggin's avatar
Nick Piggin committed
512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
}

/*
 * Free a region of KVA allocated by alloc_vmap_area
 */
static void free_vmap_area(struct vmap_area *va)
{
	spin_lock(&vmap_area_lock);
	__free_vmap_area(va);
	spin_unlock(&vmap_area_lock);
}

/*
 * Clear the pagetable entries of a given vmap_area
 */
static void unmap_vmap_area(struct vmap_area *va)
{
	vunmap_page_range(va->va_start, va->va_end);
}

532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552
static void vmap_debug_free_range(unsigned long start, unsigned long end)
{
	/*
	 * Unmap page tables and force a TLB flush immediately if
	 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
	 * bugs similarly to those in linear kernel virtual address
	 * space after a page has been freed.
	 *
	 * All the lazy freeing logic is still retained, in order to
	 * minimise intrusiveness of this debugging feature.
	 *
	 * This is going to be *slow* (linear kernel virtual address
	 * debugging doesn't do a broadcast TLB flush so it is a lot
	 * faster).
	 */
#ifdef CONFIG_DEBUG_PAGEALLOC
	vunmap_page_range(start, end);
	flush_tlb_kernel_range(start, end);
#endif
}

Nick Piggin's avatar
Nick Piggin committed
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579
/*
 * lazy_max_pages is the maximum amount of virtual address space we gather up
 * before attempting to purge with a TLB flush.
 *
 * There is a tradeoff here: a larger number will cover more kernel page tables
 * and take slightly longer to purge, but it will linearly reduce the number of
 * global TLB flushes that must be performed. It would seem natural to scale
 * this number up linearly with the number of CPUs (because vmapping activity
 * could also scale linearly with the number of CPUs), however it is likely
 * that in practice, workloads might be constrained in other ways that mean
 * vmap activity will not scale linearly with CPUs. Also, I want to be
 * conservative and not introduce a big latency on huge systems, so go with
 * a less aggressive log scale. It will still be an improvement over the old
 * code, and it will be simple to change the scale factor if we find that it
 * becomes a problem on bigger systems.
 */
static unsigned long lazy_max_pages(void)
{
	unsigned int log;

	log = fls(num_online_cpus());

	return log * (32UL * 1024 * 1024 / PAGE_SIZE);
}

static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);

580 581 582
/* for per-CPU blocks */
static void purge_fragmented_blocks_allcpus(void);

583 584 585 586 587 588 589 590 591
/*
 * called before a call to iounmap() if the caller wants vm_area_struct's
 * immediately freed.
 */
void set_iounmap_nonlazy(void)
{
	atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
}

Nick Piggin's avatar
Nick Piggin committed
592 593 594 595 596 597 598 599 600 601 602 603 604
/*
 * Purges all lazily-freed vmap areas.
 *
 * If sync is 0 then don't purge if there is already a purge in progress.
 * If force_flush is 1, then flush kernel TLBs between *start and *end even
 * if we found no lazy vmap areas to unmap (callers can use this to optimise
 * their own TLB flushing).
 * Returns with *start = min(*start, lowest purged address)
 *              *end = max(*end, highest purged address)
 */
static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
					int sync, int force_flush)
{
605
	static DEFINE_SPINLOCK(purge_lock);
Nick Piggin's avatar
Nick Piggin committed
606 607
	LIST_HEAD(valist);
	struct vmap_area *va;
608
	struct vmap_area *n_va;
Nick Piggin's avatar
Nick Piggin committed
609 610 611 612 613 614 615 616
	int nr = 0;

	/*
	 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
	 * should not expect such behaviour. This just simplifies locking for
	 * the case that isn't actually used at the moment anyway.
	 */
	if (!sync && !force_flush) {
617
		if (!spin_trylock(&purge_lock))
Nick Piggin's avatar
Nick Piggin committed
618 619
			return;
	} else
620
		spin_lock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
621

622 623 624
	if (sync)
		purge_fragmented_blocks_allcpus();

Nick Piggin's avatar
Nick Piggin committed
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639
	rcu_read_lock();
	list_for_each_entry_rcu(va, &vmap_area_list, list) {
		if (va->flags & VM_LAZY_FREE) {
			if (va->va_start < *start)
				*start = va->va_start;
			if (va->va_end > *end)
				*end = va->va_end;
			nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
			list_add_tail(&va->purge_list, &valist);
			va->flags |= VM_LAZY_FREEING;
			va->flags &= ~VM_LAZY_FREE;
		}
	}
	rcu_read_unlock();

640
	if (nr)
Nick Piggin's avatar
Nick Piggin committed
641 642 643 644 645 646 647
		atomic_sub(nr, &vmap_lazy_nr);

	if (nr || force_flush)
		flush_tlb_kernel_range(*start, *end);

	if (nr) {
		spin_lock(&vmap_area_lock);
648
		list_for_each_entry_safe(va, n_va, &valist, purge_list)
Nick Piggin's avatar
Nick Piggin committed
649 650 651
			__free_vmap_area(va);
		spin_unlock(&vmap_area_lock);
	}
652
	spin_unlock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
653 654
}

Nick Piggin's avatar
Nick Piggin committed
655 656 657 658 659 660 661 662 663 664 665
/*
 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
 * is already purging.
 */
static void try_purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

	__purge_vmap_area_lazy(&start, &end, 0, 0);
}

Nick Piggin's avatar
Nick Piggin committed
666 667 668 669 670 671 672
/*
 * Kick off a purge of the outstanding lazy areas.
 */
static void purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

Nick Piggin's avatar
Nick Piggin committed
673
	__purge_vmap_area_lazy(&start, &end, 1, 0);
Nick Piggin's avatar
Nick Piggin committed
674 675 676
}

/*
677 678 679
 * Free a vmap area, caller ensuring that the area has been unmapped
 * and flush_cache_vunmap had been called for the correct range
 * previously.
Nick Piggin's avatar
Nick Piggin committed
680
 */
681
static void free_vmap_area_noflush(struct vmap_area *va)
Nick Piggin's avatar
Nick Piggin committed
682 683 684 685
{
	va->flags |= VM_LAZY_FREE;
	atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
	if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
Nick Piggin's avatar
Nick Piggin committed
686
		try_purge_vmap_area_lazy();
Nick Piggin's avatar
Nick Piggin committed
687 688
}

689 690 691 692 693 694 695 696 697 698
/*
 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
 * called for the correct range previously.
 */
static void free_unmap_vmap_area_noflush(struct vmap_area *va)
{
	unmap_vmap_area(va);
	free_vmap_area_noflush(va);
}

699 700 701 702 703 704 705 706 707
/*
 * Free and unmap a vmap area
 */
static void free_unmap_vmap_area(struct vmap_area *va)
{
	flush_cache_vunmap(va->va_start, va->va_end);
	free_unmap_vmap_area_noflush(va);
}

Nick Piggin's avatar
Nick Piggin committed
708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751
static struct vmap_area *find_vmap_area(unsigned long addr)
{
	struct vmap_area *va;

	spin_lock(&vmap_area_lock);
	va = __find_vmap_area(addr);
	spin_unlock(&vmap_area_lock);

	return va;
}

static void free_unmap_vmap_area_addr(unsigned long addr)
{
	struct vmap_area *va;

	va = find_vmap_area(addr);
	BUG_ON(!va);
	free_unmap_vmap_area(va);
}


/*** Per cpu kva allocator ***/

/*
 * vmap space is limited especially on 32 bit architectures. Ensure there is
 * room for at least 16 percpu vmap blocks per CPU.
 */
/*
 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
 * to #define VMALLOC_SPACE		(VMALLOC_END-VMALLOC_START). Guess
 * instead (we just need a rough idea)
 */
#if BITS_PER_LONG == 32
#define VMALLOC_SPACE		(128UL*1024*1024)
#else
#define VMALLOC_SPACE		(128UL*1024*1024*1024)
#endif

#define VMALLOC_PAGES		(VMALLOC_SPACE / PAGE_SIZE)
#define VMAP_MAX_ALLOC		BITS_PER_LONG	/* 256K with 4K pages */
#define VMAP_BBMAP_BITS_MAX	1024	/* 4MB with 4K pages */
#define VMAP_BBMAP_BITS_MIN	(VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y)		((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y)		((x) > (y) ? (x) : (y)) /* can't use max() */
752 753 754 755
#define VMAP_BBMAP_BITS		\
		VMAP_MIN(VMAP_BBMAP_BITS_MAX,	\
		VMAP_MAX(VMAP_BBMAP_BITS_MIN,	\
			VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
Nick Piggin's avatar
Nick Piggin committed
756 757 758

#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)

759 760
static bool vmap_initialized __read_mostly = false;

Nick Piggin's avatar
Nick Piggin committed
761 762 763 764 765 766 767 768 769
struct vmap_block_queue {
	spinlock_t lock;
	struct list_head free;
};

struct vmap_block {
	spinlock_t lock;
	struct vmap_area *va;
	unsigned long free, dirty;
770
	unsigned long dirty_min, dirty_max; /*< dirty range */
771 772
	struct list_head free_list;
	struct rcu_head rcu_head;
773
	struct list_head purge;
Nick Piggin's avatar
Nick Piggin committed
774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800
};

/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);

/*
 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
 * in the free path. Could get rid of this if we change the API to return a
 * "cookie" from alloc, to be passed to free. But no big deal yet.
 */
static DEFINE_SPINLOCK(vmap_block_tree_lock);
static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);

/*
 * We should probably have a fallback mechanism to allocate virtual memory
 * out of partially filled vmap blocks. However vmap block sizing should be
 * fairly reasonable according to the vmalloc size, so it shouldn't be a
 * big problem.
 */

static unsigned long addr_to_vb_idx(unsigned long addr)
{
	addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
	addr /= VMAP_BLOCK_SIZE;
	return addr;
}

801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818
static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
{
	unsigned long addr;

	addr = va_start + (pages_off << PAGE_SHIFT);
	BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
	return (void *)addr;
}

/**
 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
 *                  block. Of course pages number can't exceed VMAP_BBMAP_BITS
 * @order:    how many 2^order pages should be occupied in newly allocated block
 * @gfp_mask: flags for the page level allocator
 *
 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
 */
static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
Nick Piggin's avatar
Nick Piggin committed
819 820 821 822 823 824
{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
	struct vmap_area *va;
	unsigned long vb_idx;
	int node, err;
825
	void *vaddr;
Nick Piggin's avatar
Nick Piggin committed
826 827 828 829 830 831 832 833 834 835 836

	node = numa_node_id();

	vb = kmalloc_node(sizeof(struct vmap_block),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!vb))
		return ERR_PTR(-ENOMEM);

	va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
					VMALLOC_START, VMALLOC_END,
					node, gfp_mask);
837
	if (IS_ERR(va)) {
Nick Piggin's avatar
Nick Piggin committed
838
		kfree(vb);
Julia Lawall's avatar
Julia Lawall committed
839
		return ERR_CAST(va);
Nick Piggin's avatar
Nick Piggin committed
840 841 842 843 844 845 846 847 848
	}

	err = radix_tree_preload(gfp_mask);
	if (unlikely(err)) {
		kfree(vb);
		free_vmap_area(va);
		return ERR_PTR(err);
	}

849
	vaddr = vmap_block_vaddr(va->va_start, 0);
Nick Piggin's avatar
Nick Piggin committed
850 851
	spin_lock_init(&vb->lock);
	vb->va = va;
852 853 854
	/* At least something should be left free */
	BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
	vb->free = VMAP_BBMAP_BITS - (1UL << order);
Nick Piggin's avatar
Nick Piggin committed
855
	vb->dirty = 0;
856 857
	vb->dirty_min = VMAP_BBMAP_BITS;
	vb->dirty_max = 0;
Nick Piggin's avatar
Nick Piggin committed
858 859 860 861 862 863 864 865 866 867 868
	INIT_LIST_HEAD(&vb->free_list);

	vb_idx = addr_to_vb_idx(va->va_start);
	spin_lock(&vmap_block_tree_lock);
	err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(err);
	radix_tree_preload_end();

	vbq = &get_cpu_var(vmap_block_queue);
	spin_lock(&vbq->lock);
869
	list_add_tail_rcu(&vb->free_list, &vbq->free);
Nick Piggin's avatar
Nick Piggin committed
870
	spin_unlock(&vbq->lock);
871
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
872

873
	return vaddr;
Nick Piggin's avatar
Nick Piggin committed
874 875 876 877 878 879 880 881 882 883 884 885 886
}

static void free_vmap_block(struct vmap_block *vb)
{
	struct vmap_block *tmp;
	unsigned long vb_idx;

	vb_idx = addr_to_vb_idx(vb->va->va_start);
	spin_lock(&vmap_block_tree_lock);
	tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(tmp != vb);

887
	free_vmap_area_noflush(vb->va);
888
	kfree_rcu(vb, rcu_head);
Nick Piggin's avatar
Nick Piggin committed
889 890
}

891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907
static void purge_fragmented_blocks(int cpu)
{
	LIST_HEAD(purge);
	struct vmap_block *vb;
	struct vmap_block *n_vb;
	struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);

	rcu_read_lock();
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {

		if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
			continue;

		spin_lock(&vb->lock);
		if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
			vb->free = 0; /* prevent further allocs after releasing lock */
			vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
908 909
			vb->dirty_min = 0;
			vb->dirty_max = VMAP_BBMAP_BITS;
910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933
			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
			spin_unlock(&vb->lock);
			list_add_tail(&vb->purge, &purge);
		} else
			spin_unlock(&vb->lock);
	}
	rcu_read_unlock();

	list_for_each_entry_safe(vb, n_vb, &purge, purge) {
		list_del(&vb->purge);
		free_vmap_block(vb);
	}
}

static void purge_fragmented_blocks_allcpus(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		purge_fragmented_blocks(cpu);
}

Nick Piggin's avatar
Nick Piggin committed
934 935 936 937
static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
938
	void *vaddr = NULL;
Nick Piggin's avatar
Nick Piggin committed
939 940
	unsigned int order;

941
	BUG_ON(offset_in_page(size));
Nick Piggin's avatar
Nick Piggin committed
942
	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
943 944 945 946 947 948 949 950
	if (WARN_ON(size == 0)) {
		/*
		 * Allocating 0 bytes isn't what caller wants since
		 * get_order(0) returns funny result. Just warn and terminate
		 * early.
		 */
		return NULL;
	}
Nick Piggin's avatar
Nick Piggin committed
951 952 953 954 955
	order = get_order(size);

	rcu_read_lock();
	vbq = &get_cpu_var(vmap_block_queue);
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
956
		unsigned long pages_off;
Nick Piggin's avatar
Nick Piggin committed
957 958

		spin_lock(&vb->lock);
959 960 961 962
		if (vb->free < (1UL << order)) {
			spin_unlock(&vb->lock);
			continue;
		}
963

964 965
		pages_off = VMAP_BBMAP_BITS - vb->free;
		vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
966 967 968 969 970 971
		vb->free -= 1UL << order;
		if (vb->free == 0) {
			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
		}
972

973 974
		spin_unlock(&vb->lock);
		break;
Nick Piggin's avatar
Nick Piggin committed
975
	}
976

977
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
978 979
	rcu_read_unlock();

980 981 982
	/* Allocate new block if nothing was found */
	if (!vaddr)
		vaddr = new_vmap_block(order, gfp_mask);
Nick Piggin's avatar
Nick Piggin committed
983

984
	return vaddr;
Nick Piggin's avatar
Nick Piggin committed
985 986 987 988 989 990 991 992 993
}

static void vb_free(const void *addr, unsigned long size)
{
	unsigned long offset;
	unsigned long vb_idx;
	unsigned int order;
	struct vmap_block *vb;

994
	BUG_ON(offset_in_page(size));
Nick Piggin's avatar
Nick Piggin committed
995
	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
996 997 998

	flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);

Nick Piggin's avatar
Nick Piggin committed
999 1000 1001
	order = get_order(size);

	offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1002
	offset >>= PAGE_SHIFT;
Nick Piggin's avatar
Nick Piggin committed
1003 1004 1005 1006 1007 1008 1009

	vb_idx = addr_to_vb_idx((unsigned long)addr);
	rcu_read_lock();
	vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
	rcu_read_unlock();
	BUG_ON(!vb);

1010 1011
	vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);

Nick Piggin's avatar
Nick Piggin committed
1012
	spin_lock(&vb->lock);
1013 1014 1015 1016

	/* Expand dirty range */
	vb->dirty_min = min(vb->dirty_min, offset);
	vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1017

Nick Piggin's avatar
Nick Piggin committed
1018 1019
	vb->dirty += 1UL << order;
	if (vb->dirty == VMAP_BBMAP_BITS) {
1020
		BUG_ON(vb->free);
Nick Piggin's avatar
Nick Piggin committed
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
		spin_unlock(&vb->lock);
		free_vmap_block(vb);
	} else
		spin_unlock(&vb->lock);
}

/**
 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
 *
 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
 * to amortize TLB flushing overheads. What this means is that any page you
 * have now, may, in a former life, have been mapped into kernel virtual
 * address by the vmap layer and so there might be some CPUs with TLB entries
 * still referencing that page (additional to the regular 1:1 kernel mapping).
 *
 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
 * be sure that none of the pages we have control over will have any aliases
 * from the vmap layer.
 */
void vm_unmap_aliases(void)
{
	unsigned long start = ULONG_MAX, end = 0;
	int cpu;
	int flush = 0;

1046 1047 1048
	if (unlikely(!vmap_initialized))
		return;

Nick Piggin's avatar
Nick Piggin committed
1049 1050 1051 1052 1053 1054 1055
	for_each_possible_cpu(cpu) {
		struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
		struct vmap_block *vb;

		rcu_read_lock();
		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
			spin_lock(&vb->lock);
1056 1057
			if (vb->dirty) {
				unsigned long va_start = vb->va->va_start;
Nick Piggin's avatar
Nick Piggin committed
1058
				unsigned long s, e;
1059

1060 1061
				s = va_start + (vb->dirty_min << PAGE_SHIFT);
				e = va_start + (vb->dirty_max << PAGE_SHIFT);
Nick Piggin's avatar
Nick Piggin committed
1062

1063 1064
				start = min(s, start);
				end   = max(e, end);
Nick Piggin's avatar
Nick Piggin committed
1065

1066
				flush = 1;
Nick Piggin's avatar
Nick Piggin committed
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092
			}
			spin_unlock(&vb->lock);
		}
		rcu_read_unlock();
	}

	__purge_vmap_area_lazy(&start, &end, 1, flush);
}
EXPORT_SYMBOL_GPL(vm_unmap_aliases);

/**
 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
 * @mem: the pointer returned by vm_map_ram
 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
 */
void vm_unmap_ram(const void *mem, unsigned int count)
{
	unsigned long size = count << PAGE_SHIFT;
	unsigned long addr = (unsigned long)mem;

	BUG_ON(!addr);
	BUG_ON(addr < VMALLOC_START);
	BUG_ON(addr > VMALLOC_END);
	BUG_ON(addr & (PAGE_SIZE-1));

	debug_check_no_locks_freed(mem, size);
1093
	vmap_debug_free_range(addr, addr+size);
Nick Piggin's avatar
Nick Piggin committed
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107

	if (likely(count <= VMAP_MAX_ALLOC))
		vb_free(mem, size);
	else
		free_unmap_vmap_area_addr(addr);
}
EXPORT_SYMBOL(vm_unmap_ram);

/**
 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
 * @pages: an array of pointers to the pages to be mapped
 * @count: number of pages
 * @node: prefer to allocate data structures on this node
 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1108
 *
1109 1110 1111 1112 1113 1114
 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
 * faster than vmap so it's good.  But if you mix long-life and short-life
 * objects with vm_map_ram(), it could consume lots of address space through
 * fragmentation (especially on a 32bit machine).  You could see failures in
 * the end.  Please use this function for short-lived objects.
 *
1115
 * Returns: a pointer to the address that has been mapped, or %NULL on failure
Nick Piggin's avatar
Nick Piggin committed
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145
 */
void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
{
	unsigned long size = count << PAGE_SHIFT;
	unsigned long addr;
	void *mem;

	if (likely(count <= VMAP_MAX_ALLOC)) {
		mem = vb_alloc(size, GFP_KERNEL);
		if (IS_ERR(mem))
			return NULL;
		addr = (unsigned long)mem;
	} else {
		struct vmap_area *va;
		va = alloc_vmap_area(size, PAGE_SIZE,
				VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
		if (IS_ERR(va))
			return NULL;

		addr = va->va_start;
		mem = (void *)addr;
	}
	if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
		vm_unmap_ram(mem, count);
		return NULL;
	}
	return mem;
}
EXPORT_SYMBOL(vm_map_ram);

1146
static struct vm_struct *vmlist __initdata;
Nicolas Pitre's avatar
Nicolas Pitre committed
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172
/**
 * vm_area_add_early - add vmap area early during boot
 * @vm: vm_struct to add
 *
 * This function is used to add fixed kernel vm area to vmlist before
 * vmalloc_init() is called.  @vm->addr, @vm->size, and @vm->flags
 * should contain proper values and the other fields should be zero.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
void __init vm_area_add_early(struct vm_struct *vm)
{
	struct vm_struct *tmp, **p;

	BUG_ON(vmap_initialized);
	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
		if (tmp->addr >= vm->addr) {
			BUG_ON(tmp->addr < vm->addr + vm->size);
			break;
		} else
			BUG_ON(tmp->addr + tmp->size > vm->addr);
	}
	vm->next = *p;
	*p = vm;
}

1173 1174 1175
/**
 * vm_area_register_early - register vmap area early during boot
 * @vm: vm_struct to register
1176
 * @align: requested alignment
1177 1178 1179 1180 1181 1182 1183 1184
 *
 * This function is used to register kernel vm area before
 * vmalloc_init() is called.  @vm->size and @vm->flags should contain
 * proper values on entry and other fields should be zero.  On return,
 * vm->addr contains the allocated address.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
1185
void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1186 1187
{
	static size_t vm_init_off __initdata;
1188 1189 1190 1191
	unsigned long addr;

	addr = ALIGN(VMALLOC_START + vm_init_off, align);
	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1192

1193
	vm->addr = (void *)addr;
1194

Nicolas Pitre's avatar
Nicolas Pitre committed
1195
	vm_area_add_early(vm);
1196 1197
}

Nick Piggin's avatar
Nick Piggin committed
1198 1199
void __init vmalloc_init(void)
{
1200 1201
	struct vmap_area *va;
	struct vm_struct *tmp;
Nick Piggin's avatar
Nick Piggin committed
1202 1203 1204 1205
	int i;

	for_each_possible_cpu(i) {
		struct vmap_block_queue *vbq;
1206
		struct vfree_deferred *p;
Nick Piggin's avatar
Nick Piggin committed
1207 1208 1209 1210

		vbq = &per_cpu(vmap_block_queue, i);
		spin_lock_init(&vbq->lock);
		INIT_LIST_HEAD(&vbq->free);
1211 1212 1213
		p = &per_cpu(vfree_deferred, i);
		init_llist_head(&p->list);
		INIT_WORK(&p->wq, free_work);
Nick Piggin's avatar
Nick Piggin committed
1214
	}
1215

1216 1217
	/* Import existing vmlist entries. */
	for (tmp = vmlist; tmp; tmp = tmp->next) {
1218
		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1219
		va->flags = VM_VM_AREA;
1220 1221
		va->va_start = (unsigned long)tmp->addr;
		va->va_end = va->va_start + tmp->size;
1222
		va->vm = tmp;
1223 1224
		__insert_vmap_area(va);
	}
1225 1226 1227

	vmap_area_pcpu_hole = VMALLOC_END;

1228
	vmap_initialized = true;
Nick Piggin's avatar
Nick Piggin committed
1229 1230
}

1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
/**
 * map_kernel_range_noflush - map kernel VM area with the specified pages
 * @addr: start of the VM area to map
 * @size: size of the VM area to map
 * @prot: page protection flags to use
 * @pages: pages to map
 *
 * Map PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vmap() on to-be-mapped areas
 * before calling this function.
 *
 * RETURNS:
 * The number of pages mapped on success, -errno on failure.
 */
int map_kernel_range_noflush(unsigned long addr, unsigned long size,
			     pgprot_t prot, struct page **pages)
{
	return vmap_page_range_noflush(addr, addr + size, prot, pages);
}

/**
 * unmap_kernel_range_noflush - unmap kernel VM area
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Unmap PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
 * before calling this function and flush_tlb_kernel_range() after.
 */
void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
{
	vunmap_page_range(addr, addr + size);
}
1274
EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1275 1276 1277 1278 1279 1280 1281 1282 1283

/**
 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Similar to unmap_kernel_range_noflush() but flushes vcache before
 * the unmapping and tlb after.
 */
Nick Piggin's avatar
Nick Piggin committed
1284 1285 1286
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	unsigned long end = addr + size;
1287 1288

	flush_cache_vunmap(addr, end);
Nick Piggin's avatar
Nick Piggin committed
1289 1290 1291
	vunmap_page_range(addr, end);
	flush_tlb_kernel_range(addr, end);
}
1292
EXPORT_SYMBOL_GPL(unmap_kernel_range);
Nick Piggin's avatar
Nick Piggin committed
1293

1294
int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
Nick Piggin's avatar
Nick Piggin committed
1295 1296
{
	unsigned long addr = (unsigned long)area->addr;
1297
	unsigned long end = addr + get_vm_area_size(area);
Nick Piggin's avatar
Nick Piggin committed
1298 1299
	int err;

1300
	err = vmap_page_range(addr, end, prot, pages);
Nick Piggin's avatar
Nick Piggin committed
1301

1302
	return err > 0 ? 0 : err;
Nick Piggin's avatar
Nick Piggin committed
1303 1304 1305
}
EXPORT_SYMBOL_GPL(map_vm_area);

1306
static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1307
			      unsigned long flags, const void *caller)
1308
{
1309
	spin_lock(&vmap_area_lock);
1310 1311 1312 1313
	vm->flags = flags;
	vm->addr = (void *)va->va_start;
	vm->size = va->va_end - va->va_start;
	vm->caller = caller;
1314
	va->vm = vm;
1315
	va->flags |= VM_VM_AREA;
1316
	spin_unlock(&vmap_area_lock);
1317
}
1318

1319
static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1320
{
1321
	/*
1322
	 * Before removing VM_UNINITIALIZED,
1323 1324 1325 1326
	 * we should make sure that vm has proper values.
	 * Pair with smp_rmb() in show_numa_info().
	 */
	smp_wmb();
1327
	vm->flags &= ~VM_UNINITIALIZED;
1328 1329
}

Nick Piggin's avatar
Nick Piggin committed
1330
static struct vm_struct *__get_vm_area_node(unsigned long size,
1331
		unsigned long align, unsigned long flags, unsigned long start,
1332
		unsigned long end, int node, gfp_t gfp_mask, const void *caller)
Nick Piggin's avatar
Nick Piggin committed
1333
{
1334
	struct vmap_area *va;
Nick Piggin's avatar
Nick Piggin committed
1335
	struct vm_struct *area;
Linus Torvalds's avatar
Linus Torvalds committed
1336

1337
	BUG_ON(in_interrupt());
1338
	if (flags & VM_IOREMAP)
1339 1340
		align = 1ul << clamp_t(int, fls_long(size),
				       PAGE_SHIFT, IOREMAP_MAX_ORDER);
Nick Piggin's avatar
Nick Piggin committed
1341

Linus Torvalds's avatar
Linus Torvalds committed
1342
	size = PAGE_ALIGN(size);
1343 1344
	if (unlikely(!size))
		return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1345

1346
	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
Linus Torvalds's avatar
Linus Torvalds committed
1347 1348 1349
	if (unlikely(!area))
		return NULL;

1350 1351
	if (!(flags & VM_NO_GUARD))
		size += PAGE_SIZE;
Linus Torvalds's avatar
Linus Torvalds committed
1352

Nick Piggin's avatar
Nick Piggin committed
1353 1354 1355 1356
	va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
	if (IS_ERR(va)) {
		kfree(area);
		return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1357 1358
	}

1359
	setup_vmalloc_vm(area, va, flags, caller);
1360

Linus Torvalds's avatar
Linus Torvalds committed
1361 1362 1363
	return area;
}

Christoph Lameter's avatar
Christoph Lameter committed
1364 1365 1366
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
				unsigned long start, unsigned long end)
{
David Rientjes's avatar
David Rientjes committed
1367 1368
	return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
				  GFP_KERNEL, __builtin_return_address(0));
Christoph Lameter's avatar
Christoph Lameter committed
1369
}
1370
EXPORT_SYMBOL_GPL(__get_vm_area);
Christoph Lameter's avatar
Christoph Lameter committed
1371

1372 1373
struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
				       unsigned long start, unsigned long end,
1374
				       const void *caller)
1375
{
David Rientjes's avatar
David Rientjes committed
1376 1377
	return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
				  GFP_KERNEL, caller);
1378 1379
}

Linus Torvalds's avatar
Linus Torvalds committed
1380
/**
Simon Arlott's avatar
Simon Arlott committed
1381
 *	get_vm_area  -  reserve a contiguous kernel virtual area
Linus Torvalds's avatar
Linus Torvalds committed
1382 1383 1384 1385 1386 1387 1388 1389 1390
 *	@size:		size of the area
 *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC
 *
 *	Search an area of @size in the kernel virtual mapping area,
 *	and reserved it for out purposes.  Returns the area descriptor
 *	on success or %NULL on failure.
 */
struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
{
1391
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
David Rientjes's avatar
David Rientjes committed
1392 1393
				  NUMA_NO_NODE, GFP_KERNEL,
				  __builtin_return_address(0));
1394 1395 1396
}

struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1397
				const void *caller)
1398
{
1399
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
David Rientjes's avatar
David Rientjes committed
1400
				  NUMA_NO_NODE, GFP_KERNEL, caller);
Linus Torvalds's avatar
Linus Torvalds committed
1401 1402
}

1403 1404 1405 1406 1407 1408 1409 1410 1411
/**
 *	find_vm_area  -  find a continuous kernel virtual area
 *	@addr:		base address
 *
 *	Search for the kernel VM area starting at @addr, and return it.
 *	It is up to the caller to do all required locking to keep the returned
 *	pointer valid.
 */
struct vm_struct *find_vm_area(const void *addr)
1412
{
Nick Piggin's avatar
Nick Piggin committed
1413
	struct vmap_area *va;
1414

Nick Piggin's avatar
Nick Piggin committed
1415 1416
	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA)
1417
		return va->vm;
Linus Torvalds's avatar
Linus Torvalds committed
1418 1419 1420 1421

	return NULL;
}

1422
/**
Simon Arlott's avatar
Simon Arlott committed
1423
 *	remove_vm_area  -  find and remove a continuous kernel virtual area
1424 1425 1426 1427 1428 1429
 *	@addr:		base address
 *
 *	Search for the kernel VM area starting at @addr, and remove it.
 *	This function returns the found VM area, but using it is NOT safe
 *	on SMP machines, except for its size or flags.
 */
1430
struct vm_struct *remove_vm_area(const void *addr)
1431
{
Nick Piggin's avatar
Nick Piggin committed
1432 1433 1434 1435
	struct vmap_area *va;

	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA